An apparatus of the aforementioned type is proposed in, for example, EP-A-238 461, wherein the stylet, a so-called Tru-cut-Needle has a lateral receptacle. Under the action of a first spring, the Tru-cut-Needle is introduced into the biopsy area, so that the tissue is forced into the lateral recess. The hollow needle is then moved in the same direction over the recess, so that the tissue pressed into the latter is cut off and held by the Tru-cut-Needle, and the hollow needle and the stylet are moved jointly, with both needles being removed from the body so as to supply a tissue core for further investigation.
A similar but more complicated apparatus is proposed in, for example, WO83/03343.
EP-A-10 321 and EP-A-153 047 also disclose apparatuses wherein the stylet, having lateral indentations, is manually advanced and only the hollow needle is moved by spring action.